Currently, the USA FDA has approved the EnSeal device for vessels up to 7 mm in diameter. This is equal or greater to other vessel sealing systems that are widely used such as Ligasure (7 mm) and Harmonic Scalpel (5 mm). Porcine studies done by SurgRx as well as research groups from Cleveland Clinic - FL and Carolinas Medical Center demonstrate the safety of this device in its approved size range when compared to other devices. In these studies, they find that the EnSeal has significantly higher burst pressures on sealed vessels than other sealing systems (678 mm Hg for EnSeal vs 489 mm Hg for Ligasure) or that there is no statistical difference, but that it seals at supra-physiologic pressures (891 mm Hg EnSeal vs 884 mm Hg Ligasure).1, 2 These measurements are obtained by securing the open end of a vessel to a device that fills the lumen with fluid. Once the seal on the other end bursts, the machine records the final pressure reading within the lumen of the vessel. Other notable findings of the EnSeal include less adventitial damage to the vessels on histopathologic evaluation and minimal failure rates (only 1/39 vessels failed to seal).1, 2 A study completed from Turkey used EnSeal on rat liver parenchyma and compared it to Ligasure and conventional methods for liver resection. Sahin and colleagues found that EnSeal was at least as effective as conventional techniques and that there was less inflammation and damage due to thermal spread to the rat liver parenchyma when compared to Ligasure.16 In a comparison of two ultrasonic devices on human vessels, Ching found that veins have a decreasing burst pressure as the diameter of the vessels increase.17 These burst pressures are much lower than what is reported in porcine arteries. This finding makes it important to determine the seal bursting pressure in human vessels so that the relationship between experimental values in porcine models can be clinically correlated. Previous studies have analyzed the histopathologic effect of the EnSeal device on the blood vessels.2 We will also do an analysis of human tissue.